Rear caliper piston

[Gaz mr-s]

I bought refurbished rear calipers from Simon Sinclair last year.  I've taken the discs of for a clean-up & am trying to re-fit.
The caliper won't go over the pads. (same pads, few miles) I didn't expect to have to turn the piston in, but it wasn't going over. So I'm turning, & turning.... & I don't the piston is going back in at all.

Has anyone come across this before?

[Carolyn]

I suspect the calliper isn't fully expanded?

[Gaz mr-s]

Don't understand what you mean C, ??

[Carolyn]

Don't understand what you mean C, ??

all the way out on its sliders.

[jonbill]

screwing alone isn't enough, you have to press too. And what Carolyn said.

[Gaz mr-s]

Don't understand what you mean C, ??

all the way out on its sliders.

Misunderstanding maybe..... sliding no problem, caliper engaging over outside pad, but piston bumping into pad backplate.  I could try more force onto it.

[Carolyn]

Are you holding the disc steady with a wheel nut?

[Gaz mr-s]

Are you holding the disc steady with a wheel nut?

Yep... two.

[Carolyn]

Very strange.

It's going to be something silly!

Take a break ands tart afresh tomorrow?

It's hard to know when it's not in front of you.

[Call the midlife!]

Have you got the notch aligned with the nipple on the pad?

[Joesson]

From my simplistic viewpoint the only  "adjustment " is in the position of the piston, so if the pad / disc/ pad won't fit into the caliper the piston is too far out and needs pushing back in.

[Mikeymead]

I'd better pay attention to this as I need to replace the rear pads soon, last time I did it I replaced both calipers so I never had to wind them back. Is the rotation of the piston handed to each side or are they the same?

[Gaz mr-s]

Piston come to a stop, will not turn clockwise any more, but is sticking proud of the rubber seal by about 2mm.

Grumble...

[Carolyn]

I'd better pay attention to this as I need to replace the rear pads soon, last time I did it I replaced both calipers so I never had to wind them back. Is the rotation of the piston handed to each side or are they the same?

The same. Clockwise is in.

[paulj]

Just had a look in the Toyota factory manual - that is quite "agricultural" and suggests pushing the piston in with the handle of a hammer.

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[Carolyn]

Is the nipple on the back of the pad pined up?

[Mikeymead]

I'd better pay attention to this as I need to replace the rear pads soon, last time I did it I replaced both calipers so I never had to wind them back. Is the rotation of the piston handed to each side or are they the same?

The same. Clockwise is in.

Many thanks.

[Joesson]

Just had a look in the Toyota factory manual - that is quite "agricultural" and suggests pushing the piston in with the handle of a hammer.

.....only the best from our main dealers!

A hammer shaft is typically wood, wood is softer than a brake piston, a hammer shaft length gives good leverage, a hammer can be used for many things, a specialised tool for only one.
" Pushing the piston in with the handle of a hammer"  suggests that a degree of force is required.

[Gaz mr-s]

Is the nipple on the back of the pad pined up?

That isn't relevant just now, which is why I didn't answer John above. The outer edge of the pad plate is solid, no 'cutout' sort of thing that the piston segment would slide into.

I tried taking a pic of it, but it wasn't worth posting.

[Call the midlife!]

Is the nipple on the back of the pad pined up?

That isn't relevant just now, which is why I didn't answer John above. The outer edge of the pad plate is solid, no 'cutout' sort of thing that the piston segment would slide into.

I tried taking a pic of it, but it wasn't worth posting.

There isn't a "cut out" on the pad, there's a raised bump that slides into the recess on the piston, which is very relevant if you want your handbrake to work...

[Gaz mr-s]

Is the nipple on the back of the pad pined up?

That isn't relevant just now, which is why I didn't answer John above. The outer edge of the pad plate is solid, no 'cutout' sort of thing that the piston segment would slide into.

I tried taking a pic of it, but it wasn't worth posting.

There isn't a "cut out" on the pad, there's a raised bump that slides into the recess on the piston, which is very relevant if you want your handbrake to work...

Give me some credit John....

The caliper with piston protruding is giving insufficient room to move over the pads & disc width.  As it happens the piston is pretty close rotation-wise to the correct position, but the outer edge is butting on the pad plate.

Tomorrow I'm going to wind back the other piston & see how far it goes in in comparison.

[Chilli Girl]

  Come on now John's only trying to help - It's frustrating when things don't go to plan, I know! Tomorrow's another day and hopefully it will be sorted.

[Dev]

Piston come to a stop, will not turn clockwise any more, but is sticking proud of the rubber seal by about 2mm.

Grumble...

 Have you compared it to the other caliper. Thats what I would do to see if it is in anyway abnormal between the two if its not going all the way in for clearance.

Edit: just read your last post. You are  on the right track.

[Mr2paul]

They should at least wind back to a flush position shouldn't they ?
I'm not doubting Gav here, I'm thinking summat maybe faulty ? It's an easy job, but this is a new part so may not be correct ?

[Call the midlife!]

Is the nipple on the back of the pad pined up?

That isn't relevant just now, which is why I didn't answer John above. The outer edge of the pad plate is solid, no 'cutout' sort of thing that the piston segment would slide into.

I tried taking a pic of it, but it wasn't worth posting.

There isn't a "cut out" on the pad, there's a raised bump that slides into the recess on the piston, which is very relevant if you want your handbrake to work...

Give me some credit John....

The caliper with piston protruding is giving insufficient room to move over the pads & disc width.  As it happens the piston is pretty close rotation-wise to the correct position, but the outer edge is butting on the pad plate.

Tomorrow I'm going to wind back the other piston & see how far it goes in in comparison.

It's not a question of giving anyone credit, it's about filling in the gaps for anyone less experienced with the technology using the forum as a search tool.

New users finding  the forum from a Google search on the handbrake might get confused by someone stating that the orientation of the pads and pistons isn't relevant.